RESUMO
El virus HTLV I/II es un retrovirus, muy antiguo, cuyo origen posiblemente sea su homólogo en los simios, quienes lo transmiten al humano y luego se difunde entre nuestra especie. Gracias a los adelantos científicos, se han podido establecer las tres probables entradas o rutas migratorias de nuestros antepasados entre los distintos continentes. Ellos lamentablemente desconocían que estaban infectados. En nuestros tiempos, este insignificante y tan pequeño virus presenta áreas endémicas en todo el mundo (inclusive Argentina) y es el responsable de dos enfermedades, la Paraparesia Espástica Tropical y la Leucemia T del adulto, ambas incurables. Se ha podido prevenir la diseminación del mismo por el desarrollo de pruebas de tamizaje o selección (enzimoinmunoensayo) y suplementarias (Western Blot), como también por el asesoramiento médico de los individuos infectados.
Assuntos
Humanos , Infecções por HTLV-I/diagnóstico , Infecções por HTLV-I/epidemiologia , Infecções por HTLV-I/história , Infecções por HTLV-I/terapia , Infecções por HTLV-I/transmissão , Infecções por HTLV-II/diagnóstico , Infecções por HTLV-II/epidemiologia , Infecções por HTLV-II/história , Infecções por HTLV-II/terapia , Infecções por HTLV-II/transmissão , Argentina/epidemiologia , Filogenia , Replicação Viral/fisiologia , Sobreviventes , Técnicas Imunoenzimáticas/métodos , Testes Sorológicos , Vírus Linfotrópico T Tipo 1 Humano/fisiologia , Vírus Linfotrópico T Tipo 1 Humano/ultraestrutura , /fisiologia , /ultraestrutura , Western Blotting/métodosRESUMO
Nowadays, Brazil may be considered an endemic area for HTLV-I infection. Several studies showed a high incidence of HTLV-I infection among the general population and different groups such as blood donors, hemophiliacs, hematological and neurological patients. Cases of adult T-cell leukemia/lymphoma as well as tropical spastic paraparesis/HTLV-I associated myelopathy have been already described. Therefore the use of different technical approaches, to characterize Brazilian HTLV strains has become important. HTLV particles were characterized and recognized by the use of transmission electron microscopy in lymphocyte cocultures. The ultra-structural analysis revealed typical virus particles close to the lymphocyte membrane. The immunoelectron microscopy allowed the identification of the virus as HTLV, a type C oncovirus, group HTLV-BLV. The ethanol phosphotungstic acid technique showed structures similar to the virus budding process and the routine preparations have contributed to the analysis of the first virus-cell interaction events. Structures related to the endocytic route HTLV entrance are also pointed out.
Assuntos
Humanos , Vírus Linfotrópico T Tipo 1 Humano/ultraestrutura , Brasil , Histocitoquímica , Microscopia Eletrônica , Microscopia ImunoeletrônicaRESUMO
Some Brazilian regions are considered to be endemic for human T-cell leukemia/lymphoma virus type I (HTLV-I) infection. Several studies have shown a high prevalence of HTLV-I infection among different groups such as blood donors, hemophiliacs and patients suffering from hematological and neurological diseases. Cases of adult T -cell leukemia/lymphoma as well as tropical spastic paraparesis/HTLV-i-infected T -cell line (ROB) expressing viral antigens was established and reverse transcriptase activity could be detected in the culture supernatant. Ultrastructural analysis showed immature and mature HTLV retrovirus particles. Finally, HTLV-I provirus type I was demonstrated by the plymerase chain reaction. This is the first isolation completely carried out in Latin America. The molecular analysis of viral strains, now in progress, should clarify the molecular epidemiology of HTLV-I in Brazil